Training a dialog system using user feedback

ABSTRACT

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for training a dialog system using user feedback. According to one implementation, a method includes receiving, by a dialog engine, a first input that specifies a question; providing, by the dialog engine, an answer to the question; receiving, by the dialog engine, a second input; and determining, by the dialog engine, that the second input is classified as feedback to the answer, then determining a feedback score associated with the second input.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. ProvisionalApplication No. 61/654,512, filed Jun. 1, 2012, U.S. ProvisionalApplication No. 61/654,437, filed Jun. 1, 2012, U.S. ProvisionalApplication No. 61/654,746, filed Jun. 1, 2012, and U.S. ProvisionalApplication No. 61/654,518, filed Jun. 1, 2012, all of which are herebyincorporated herein by reference.

BACKGROUND

This specification generally relates to dialog systems, and oneparticular implementation relates to determining that an input from auser is feedback to a previously provided answer.

SUMMARY

According to one innovative aspect of the subject matter described inthis specification, an input that is received from a user of a dialogsystem after a question-answer interaction between the user and thedialog system is evaluated to determine whether the input is feedback tothe answer previously provided by the dialog system. If the input isdetermined as feedback, the dialog system may classify the input aspositive or negative feedback to the answer. If the dialog systemclassifies the input as negative feedback, the dialog system may providean alternative answer to the question.

According to another innovative aspect of the subject matter describedin this specification, a method includes receiving a first input thatspecifies a question. The method also includes providing an answer tothe question, receiving a second input, and determining that the secondinput is classified as feedback to the answer, then determining afeedback score associated with the second input.

Other implementations of this aspect include corresponding systems,apparatus, and computer programs, configured to perform the actions ofthe methods, encoded on computer storage devices.

These and other implementations can each optionally include one or moreof the following features. For instance, the method includes determiningthat the second input is classified as feedback by determining that atime difference between a time associated with providing the answer anda time associated with receiving the second input is within apredetermined time; the method includes determining that the secondinput is classified as feedback by determining that the second input isreceived after providing the answer to the question; the method includesdetermining that the second input is classified as feedback bydetermining that the second input is semantically similar to the firstinput; the method includes determining that the second input isclassified as feedback by identifying an action associated with thesecond input; the method includes identifying the action as calling atelephone number associated with the answer, or sending an email to anemail address associated with the answer; the method includes the firstinput and the second input are spoken input.

According to another innovative aspect of the subject matter describedin this specification, a method includes receiving a voice input. Themethod also includes determining that the received voice inputrepresents feedback to an answer of a question, identifying apredetermined feedback score associated with the feedback, and adjustinga confidence score associated with the question and the answer based onthe predetermined feedback score.

Other implementations of this aspect include corresponding systems,apparatus, and computer programs, configured to perform the actions ofthe methods, encoded on computer storage devices.

These and other implementations can each optionally include one or moreof the following features. For instance, the method includes beforereceiving the voice input representing the feedback to the answer,receiving, from the computing device, an additional voice input thatspecifies the question, and providing, to the computing device, theanswer to the question; the method includes normalizing the feedback,and identifying the predetermined feedback score based on the normalizedfeedback; the method includes determining the predetermined feedbackscore is lower than a threshold, and classifying the feedback asnegative feedback, where the confidence score is adjusted lower based onclassifying the feedback as negative feedback; the method includes afteradjusting the confidence score, identifying a second answer to thequestion, where a confidence score associated with the question and thesecond answer is higher than the adjusted confidence score associatedwith the question and the answer, and providing, to the computingdevice, the second answer; the method includes determining thepredetermined feedback score is higher than a threshold, and classifyingthe feedback as positive feedback, where the confidence score isadjusted higher based on classifying the feedback as positive feedback;the method includes receiving, from a different computing device, asecond voice input, determining that the second voice input representsfeedback to the answer, identifying a second predetermined feedbackscore associated with the feedback from the different computing device,and adjusting the confidence score associated with the question and theanswer based on the feedback from the computing device and the feedbackfrom the different computing device.

Advantageous implementations may include one or more of the followingfeatures. By identifying feedback associated with an answer, a systemmay gauge a user's likely attitude toward an answer—e.g., satisfaction,dissatisfaction, or ambivalence. The system may use this feedback toimprove its question-answering capability—e.g., may allow the system todynamically improve answers provided to questions—thus improving users'experience. The system may provide a follow-up answer when a user'sfeedback indicates dissatisfaction with an answer to improve a user'sexperience.

The details of one or more implementations are set forth in theaccompanying drawings and the description below. Other potentialfeatures and advantages will become apparent from the description, thedrawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one or more implementationsdescribed herein and, together with the description, explain theseimplementations.

FIGS. 1A-2E illustrate an overview of example implementations describedherein;

FIG. 3 illustrates an example environment in which systems and/ormethods described herein may be implemented;

FIG. 4 shows an example of a generic computer device and a genericmobile computer device according to one or more implementations;

FIG. 5 illustrates example functional components of a dialog engine inaccordance with one or more implementations;

FIG. 6 illustrates an example data structure that may be stored by afeedback score repository, according to one or more implementationsdescribed herein;

FIG. 7 illustrates an example data structure that may be stored by aquestion-answer score repository, according to one or moreimplementations described herein;

FIGS. 8 and 9 illustrate flowcharts of example processes for generatingor modifying a score for a question-answer pair based on user feedback,according to one or more implementations described herein;

FIG. 10 illustrates a flowchart of an example process for generating ormodifying a score for user feedback, according to one or moreimplementations described herein;

FIGS. 11A-12E illustrate examples of generating or modifying a score foruser feedback, according to one or more implementations describedherein;

FIG. 13 illustrates a flowchart of an example process for providing afollow-up answer based on feedback, according to one or moreimplementations described herein; and

FIGS. 14A-14I illustrate an example of providing a follow-up answer andgenerating or modifying a question-answer pair score associated with aquestion and the follow-up answer, according to one or moreimplementations described herein.

In the drawings, like reference numbers represent corresponding partsthroughout.

DETAILED DESCRIPTION

Devices implementing a dialog system may store information thatindicates the strength of an answer when provided in response to aparticular question. In other words, such devices may store confidencescores for question-answer pairs. A particular confidence score mayindicate a relevance of a particular answer to a particular question.

A system and/or method, described herein, may enable one or more devicesto generate or modify question-answer pair scores based on userfeedback, such as feedback that a user provides after a user deviceoutputs an answer that responds to the user's question. In someimplementations, the user device may provide a follow-up answer after auser responds in a way that is characterized as dissatisfaction with anoriginal answer.

FIGS. 1A-2E illustrate an overview of example implementations describedherein. For example, as shown in FIG. 1A, a user 105 may ask a question,“Who invented the telephone?” to a user device 110. As shown in FIG. 1B,the user device 110 may answer “Alexander Graham Bell.” As shown in FIG.1C, the user 105 may provide feedback, such as speaking the word“Thanks.” Based on this feedback being characterized as positivefeedback, and as shown in FIG. 1D, the user device 110 may storeinformation indicating that the answer “Alexander Graham Bell” is a goodanswer to the question “Who invented the telephone?”

FIG. 2A illustrates a user 105 asking a question “What was the highestgrossing romantic comedy of 2003?” to a user device 110. As shown inFIG. 2B, the user device 110 may answer “Gigli.” As shown in FIG. 2C,the user 105 may provide feedback, such as speaking the phrase “Thatcan't be right.” Based on this feedback being characterized as negativefeedback, and as shown in FIG. 2D, the user device 110 may storeinformation indicating that the answer “Gigli” is not a good answer tothe question “What was the highest grossing romantic comedy of 2003?” Asshown in FIG. 2E, the user device 110 may provide a follow-up answer,“‘How to Lose a Guy in 10 Days’ may be a better answer.” This follow-upanswer may include an alternative answer—“How to Lose a Guy in 10 Days”in this example—that is more accurate than the answer provided in FIG.2B, with which the user 105 expressed his dissatisfaction in FIG. 2C.Furthermore, the follow-up answer may include an indication that theanswer is a follow-up to the answer provided in FIG. 2B by, for example,including the phrase “may be a better answer.”

FIG. 3 is a diagram of an example environment 300 in which systemsand/or methods described herein may be implemented. Environment 300 mayinclude a user device 305 and servers, such as a question-answer pairscore repository server 310, a feedback classifier server 312 that mayinclude a feedback score repository server 315, and a search engineserver 320, herein collectively referred to as “servers 310-320,”connected to a network 325. One user device 305 and servers 310-320 havebeen illustrated as connected to network 325 for simplicity. Inpractice, environment 300 may include additional user devices and/orservers or fewer user devices and/or servers. Also, in some instances, auser device may perform a function of a server, and a server may performa function of a user device.

The user device 305 may include a client device, such as a mobiletelephone, a personal computer, a personal digital assistant (“PDA”), atablet computer, a laptop, or any other type of computation orcommunication device. The user device 305 may include audio input/outputdevices that allow a user to communicate with user device 305 viaspeech. For example, these audio input/output devices may include one ormore microphones and/or one or more speakers. The user device 305 mayalso include one or more visual input/output devices, such as one ormore cameras and/or one or more screens that are capable of presenting auser interface via which a user may interact.

Servers 310-320 may each be implemented as a single server device or acollection of server devices that may be co-located or remotely located.Additionally, or alternatively, two or more of servers 310-320 may beimplemented within a single, common server device or a single, commoncollection of server devices.

The question-answer pair score repository server 310 may storeinformation regarding confidence scores associated with question-answerpairs. As mentioned above, these confidence scores may each indicate arelevance of a particular answer to a particular question. In someimplementations, the question-answer pair score repository server 310may adjust a confidence score when a user is connected to one or more ofthe servers 310-320. In some implementations, the question-answer pairscore repository server 310 may adjust a confidence score offline, wherea user is not connected to the servers 310-320.

In general, the feedback classifier server 312 may classify a user'sinput as feedback to a particular answer previously provided to the userby the servers 310-320. In some implementations, the feedback classifierserver may include a feedback score repository server 315 that storesinformation regarding feedback scores. As further described below, thesescores may indicate how to interpret different types of feedback fromusers.

A search engine server 320 may implement a search engine that receivessearch queries, e.g., from the user device 305. These search queries maybe based on questions received by the user device 305. The search engineserver 320 may provide one or more results to the user device 305 inresponse to received search queries. As further described below, theuser device 305 may use the one or more results when providing an answerto a received question.

Additional servers, implementing other functions, may also beimplemented in environment 300. The additional servers may provide, forexample, web content, payment services, shopping services, socialnetworking services, etc.

Network 325 may include any type of network, such as a local areanetwork (“LAN”), a wide area network (“WAN”), a telephone network—e.g.,the Public Switched Telephone Network (“PSTN”) or a cellular network—anintranet, the Internet, or a combination of networks. User device 305and servers 310-320 may connect to network 325 via wired and/or wirelessconnections. In other words, user device 305 and/or any of servers310-320 may connect to network 325 via a wired connection, a wirelessconnection, or a combination of a wired connection and a wirelessconnection.

FIG. 4 shows an example of a generic computing device 400 and a genericmobile computing device 450, which may be used with the techniquesdescribed here. Computing device 400 and mobile computing device 450 maycorrespond to, for example, any of user device 305 and/or servers310-320. Each of user device 305 and servers 310-320 may include one ormore computing devices 400, mobile computing devices 450, or componentsof computing device 400 and/or mobile computing device 450.

Computing device 400 is intended to represent various forms of digitalcomputers, such as laptops, desktops, workstations, personal digitalassistants, servers, blade servers, mainframes, and other appropriatecomputers. Mobile computing device 450 is intended to represent variousforms of mobile devices, such as personal digital assistants, cellulartelephones, smart phones, and other similar computing devices. Thecomponents shown in FIG. 4, their connections and relationships, andtheir functions, are meant to be examples only, and are not meant tolimit implementations described and/or claimed in this document.

Computing device 400 may include a processor 402, memory 404, a storagedevice 406, a high-speed interface 408 connecting to memory 404 andhigh-speed expansion ports 410, and a low speed interface 412 connectingto low speed bus 414 and storage device 406. Each of the components 402,404, 406, 408, 410, and 412, are interconnected using various busses,and may be mounted on a common motherboard or in other manners asappropriate. Processor 402 can process instructions for execution withinthe computing device 400, including instructions stored in the memory404 or on the storage device 406 to display graphical information for agraphical user interface (“GUI”) on an external input/output device,such as display 416 coupled to high speed interface 408. In otherimplementations, multiple processors and/or multiple buses may be used,as appropriate, along with multiple memories and types of memory. Also,multiple computing devices 400 may be connected, with each deviceproviding portions of the necessary operations, e.g., as a server bank,a group of blade servers, or a multi-processor system, etc.

Memory 404 stores information within the computing device 400. In someimplementations, memory 404 includes a volatile memory unit or units. Insome implementations, memory 404 includes a non-volatile memory unit orunits. The memory 404 may also be another form of computer-readablemedium, such as a magnetic or optical disk. A computer-readable mediummay be defined as a non-transitory memory device. A memory device mayinclude space within a single physical memory device or spread acrossmultiple physical memory devices.

Storage device 406 is capable of providing mass storage for thecomputing device 400. In some implementations, storage device 406 may beor contain a computer-readable medium, such as a floppy disk device, ahard disk device, an optical disk device, or a tape device, a flashmemory or other similar solid state memory device, or an array ofdevices, including devices in a storage area network or otherconfigurations. A computer program product can be tangibly embodied inan information carrier. The computer program product may also containinstructions that, when executed, perform one or more methods, such asthose described herein. The information carrier is a computer ormachine-readable medium, such as memory 404, storage device 406, ormemory on processor 402.

High speed controller 408 manages bandwidth-intensive operations for thecomputing device 400, while low speed controller 412 manages lowerbandwidth-intensive operations. Such allocation of functions isexemplary only. In some implementations, high-speed controller 408 iscoupled to memory 404, display 416, e.g., through a graphics processoror accelerator, and to high-speed expansion ports 410, which may acceptvarious expansion cards (not shown). In this implementation, low-speedcontroller 412 is coupled to storage device 406 and low-speed expansionport 414. The low-speed expansion port, which may include variouscommunication ports, e.g., USB, Bluetooth, Ethernet, wireless Ethernet,may be coupled to one or more input/output devices, such as a keyboard,a pointing device, a scanner, or a networking device such as a switch orrouter, e.g., through a network adapter.

Computing device 400 may be implemented in a number of different forms,as shown in the figure. For example, it may be implemented as a standardserver 420, or multiple times in a group of such servers. It may also beimplemented as part of a rack server system 424. In addition, it may beimplemented in a personal computer such as a laptop computer 422.Alternatively, components from computing device 400 may be combined withother components in a mobile device (not shown), such as mobilecomputing device 450. Each of such devices may contain one or more ofcomputing devices 400, 450, and an entire system may be made up ofmultiple computing devices 400, 450 communicating with each other.

Mobile computing device 450 may include a processor 452, memory 464, aninput/output (“I/O”) device such as a display 454, a communicationinterface 466, and a transceiver 468, among other components. Mobilecomputing device 450 may also be provided with a storage device, such asa micro-drive or other device, to provide additional storage. Each ofthe components 450, 452, 464, 454, 466, and 468 are interconnected usingvarious buses, and several of the components may be mounted on a commonmotherboard or in other manners as appropriate.

Processor 452 can execute instructions within mobile computing device450, including instructions stored in memory 464. Processor 452 may beimplemented as a chipset of chips that include separate and multipleanalog and digital processors. Processor 452 may provide, for example,for coordination of the other components of mobile computing device 450,such as control of user interfaces, applications run by mobile computingdevice 450, and wireless communication by mobile computing device 450.

Processor 452 may communicate with a user through control interface 458and display interface 456 coupled to a display 454. Display 454 may be,for example, a Thin-Film-Transistor Liquid Crystal Display (“TFT LCD”)or an Organic Light Emitting Diode (“OLED”) display, or otherappropriate display technology. Display interface 456 may includeappropriate circuitry for driving display 454 to present graphical andother information to a user. Control interface 458 may receive commandsfrom a user and convert them for submission to the processor 452. Inaddition, an external interface 462 may be in communication withprocessor 452, so as to enable near area communication of mobilecomputing device 450 with other devices. External interface 462 mayprovide, for example, for wired communication in some implementations,or for wireless communication in other implementations, and multipleinterfaces may also be used.

Memory 464 stores information within mobile computing device 450. Memory464 can be implemented as one or more of a computer-readable medium ormedia, a volatile memory unit or units, or a non-volatile memory unit orunits. Expansion memory 474 may also be provided and connected to mobilecomputing device 450 through expansion interface 472, which may include,for example, a Single In Line Memory Module (“SIMM”) card interface.Such expansion memory 474 may provide extra storage space for device450, or may also store applications or other information for mobilecomputing device 450. Specifically, expansion memory 474 may includeinstructions to carry out or supplement the processes described above,and may include secure information also. Thus, for example, expansionmemory 474 may be provide as a security module for mobile computingdevice 450, and may be programmed with instructions that permit secureuse of device 450. In addition, secure applications may be provided viathe SIMM cards, along with additional information, such as placingidentifying information on the SIMM card in a non-hackable manner.

Expansion memory 474 may include, for example, flash memory and/or NVRAMmemory. In some implementations, a computer program product is tangiblyembodied in an information carrier. The computer program productcontains instructions that, when executed, perform one or more methods,such as those described above. The information carrier is a computer- ormachine-readable medium, such as the memory 464, expansion memory 474,or memory on processor 452, that may be received, for example, overtransceiver 468 or external interface 462.

Mobile computing device 450 may communicate wirelessly throughcommunication interface 466, which may include digital signal processingcircuitry where necessary. Communication interface 466 may provide forcommunications under various modes or protocols, such as GSM voicecalls, SMS, EMS, or MMS messaging, CDMA, TDMA, PDC, WCDMA, CDMA2000, orGPRS, among others. Such communication may occur, for example, throughradio-frequency transceiver 468. In addition, short-range communicationmay occur, such as using a Bluetooth, WiFi, or other such transceiver.In addition, Global Positioning System (“GPS”) receiver module 470 mayprovide additional navigation- and location-related wireless data tomobile computing device 450, which may be used as appropriate byapplications running on mobile computing device 450.

Mobile computing device 450 may also communicate audibly using audiocodec 460, which may receive spoken information from a user and convertit to usable digital information. Audio codec 460 may likewise generateaudible sound for a user, such as through a speaker, e.g., in a handsetof mobile computing device 450. Such sound may include sound from voicetelephone calls, may include recorded sound, e.g., voice messages, musicfiles, etc., and may also include sound generated by applicationsoperating on mobile computing device 450.

Mobile computing device 450 may be implemented in a number of differentforms, as shown in the figure. For example, it may be implemented as acellular telephone 480. It may also be implemented as part of a smartphone 482, personal digital assistant, or other similar mobile device.

Various implementations of the systems and techniques described hereincan be realized in digital electronic circuitry, integrated circuitry,specially designed application specific integrated circuits (“ASICs”),computer hardware, firmware, software, and/or combinations thereof.These various implementations can include implementations in one or morecomputer programs that are executable and/or interpretable on aprogrammable system including at least one programmable processor, whichmay be special or general purpose, coupled to receive data andinstructions from, and to transmit data and instructions to, a storagesystem, at least one input device, and at least one output device.

These computer programs, also known as programs, software, softwareapplications or code, include machine instructions for a programmableprocessor, and can be implemented in a high-level procedural and/orobject-oriented programming language, and/or in assembly/machinelanguage. As used in this specification, an “engine” (or “softwareengine”) refers to a software implemented input/output system thatprovides an output that is different from the input. An engine can be anencoded block of functionality, such as a library, a platform, aSoftware Development Kit (“SDK”), or an object. As used herein, theterms “machine-readable medium” and “computer-readable medium” refer toany non-transitory apparatus and/or device, e.g., magnetic discs,optical disks, memory, Programmable Logic Devices (“PLDs”), used toprovide machine instructions and/or data to a programmable processor,including a machine-readable medium that receives machine instructionsas a machine-readable signal. The term “machine-readable signal” refersto any signal used to provide machine instructions and/or data to aprogrammable processor.

To provide for interaction with a user, the systems and techniquesdescribed herein can be implemented on a computer having a displaydevice, e.g., a cathode ray tube (“CRT”) or liquid crystal display(“LCD”) monitor, for displaying information to the user and a keyboardand a pointing device, e.g., a mouse or a trackball, by which the usercan provide input to the computer. Other kinds of devices can be used toprovide for interaction with a user as well; for example, feedbackprovided to the user can be any form of sensory feedback, e.g., visualfeedback, auditory feedback, or tactile feedback; and input from theuser can be received in any form, including acoustic, speech, or tactileinput.

The systems and techniques described herein can be implemented in acomputing system that includes a back end component, e.g., as a dataserver, or that includes a middleware component, e.g., an applicationserver, or that includes a front end component, e.g., a client computerhaving a graphical user interface or a Web browser through which a usercan interact with implementations of the systems and techniquesdescribed here, or any combination of such back end, middleware, orfront end components. The components of the system can be interconnectedby any form or medium of digital data communication, e.g., acommunication network. Examples of communication networks include a LAN,a WAN, and the Internet.

FIG. 5 illustrates example functional components of a dialog engine 500.The dialog engine 500 may correspond to a user device 305, aquestion-answer pair score repository server 310, a feedback classifierserver 312, and/or a feedback score repository server 315. As shown inFIG. 5, the dialog engine 500 may include modules 505-530. Any, or all,of modules 505-530 may be implemented by one or more memory devices,such as memory 404 and/or memory 464, and/or one or more processors,such as processor 408 and/or processor 452. Furthermore, multiplemodules may be associated with the same memory device and/or processor.For example, one memory device, or one set of memory devices, may storeinformation associated with two or more of modules 505-530. Examples ofthe functionality of some or all of the functional components,illustrated in FIG. 5, are described below in conjunction with theexample scenario illustrated in FIGS. 2A-2E.

An answer generation engine 505 may receive a data representation of aquestion. In some implementations, the question may be received as audioinformation via, for example, one or more audio input devices, such as amicrophone, associated with a user device 305. Additionally, oralternatively, the question may include any other type of information,such as text information, image information, etc., received via anyinterface associated with the user device 305. For example, withreference to the example illustrated in FIG. 2A, the answer generationengine 505 may receive the question, “What was the highest grossingromantic comedy of 2003?”

Assume, in this example, that the question was provided as audioinformation. In some implementations, the answer generation engine 505may convert the audio information, associated with the question, intotext information. In other words, the answer generation engine 505 mayperform a speech-to-text process on the audio information associatedwith the question. The answer generation engine 505 may store the textinformation associated with the question for further processing.

In some implementations, the answer generation engine 505 may generatean answer to the received question. When generating the answer, theanswer generation engine 505 may provide a search query to a searchengine, such as the search engine server 320. The search query may bebased on the question. For example, the search query may include some orall of the text information associated with the question. In someimplementations, the search query may include the entire question,while, in some implementations, the search query may include only aportion of the question. When including only a portion of the question,answer generation engine 505 may omit certain words from the searchquery. These certain words may include words that are predetermined asunimportant to the question, such as “stop words,” including “the,” “a,”“is,” “at,” “on,” or the like. Additionally, or alternatively, answergeneration engine 505 may modify one or more words of the question whengenerating the search query. For example, answer generation engine 505may eliminate prefixes and/or suffixes. Continuing with the exampleabove, answer generation engine 505 of some implementations may generatethe search query, “highest grossing romantic comedy 2003.”

The answer generation engine 505 may receive one or more results thatare responsive to the search query from search engine server 320, andmay generate an answer based on the received results. The results mayeach be associated with a respective confidence score that is based onone or more of a variety of factors, such as relevance of a documentassociated with the result to the search query, a measure of quality ofa document associated with the result, an amount of traffic to and/orfrom a document associated with the result, an age of a documentassociated with the result, or any other factor associated with theresult. For example, the answer generation engine 505 may generate ananswer based on a highest-scoring result.

In addition to, or in lieu of, generating an answer based on searchresults provided by the search engine server 320, the answer generationengine 505 may generate an answer based on information received from aquestion-answer pair score repository 520. As further described below,the question-answer pair score repository 520 may store information thatcorrelates question-answer pairs—e.g., question-answer pair scores. Theanswer generation engine 505 may use this information to identify ananswer to the question. In some implementations, the answer generationengine 505 may compare the question to information stored by thequestion-answer pair score repository 520 to identify whether thequestion-answer pair score repository 520 stores information correlatingthe question to one or more answers. For instance, the answer generationengine 505 may determine whether a question, associated with aquestion-answer pair, exactly matches the received question.

Additionally, or alternatively, the answer generation engine 505 maydetermine whether a question, associated with a question-answer pair, issimilar to the received question, at least beyond a particularsimilarity threshold. The answer generation engine 505 may determine thesimilarity of the received question to a question associated with aquestion-answer pair based on one or more indicators of similarity, suchas semantic similarity, hamming distance, edit distance, or any otherindicator of similarity. Additionally, or alternatively, the answergeneration engine 505 may ignore one or more words, such as stop words,in the received question and/or in a question associated with aquestion-answer pair. For example, the answer generation engine 505 maydetermine that a question-answer pair, associated with the question,“Which romantic comedy movie made the most money in 2003?”, is similarbeyond a similarity threshold to the example received question, “Whatwas the highest grossing romantic comedy of 2003?”

In some implementations, the answer generation engine 505 may generatean answer based on the information received from the question-answerpair score repository 520. For instance, the answer generation engine505 may select a question-answer pair with a highest confidence score,out of question-answer pairs that are associated with the receivedquestion. As mentioned above, the generated answer may additionally, oralternatively, be based on one or more search results received from thesearch engine server 320. The answer generation engine 505 may outputthe answer via audio information—e.g., through one or more audio outputdevices, such as a speaker; via visual information—e.g., through one ormore visual output devices, such as a display screen; or via any othertechnique. Continuing with the above example, the answer generationengine 505 may output the answer “Gigli.”

Thus, the answer generation engine 505 may output an answer based oninformation received from the search engine server 320, based oninformation received from the question-answer pair score repository 520,or based on information received from both the search engine server 320and the question-answer pair score repository 520. Additionally, and asfurther described below, the answer generation engine 505 may alsooutput one or more follow-up answers based on a characterization of auser's feedback.

The question-answer pair scoring engine 510 may receive feedbackregarding the answer provided by the answer generation engine 505. Forexample, with reference to FIG. 2C, the user device 305 may receive thefeedback, “That can't be right.” As similarly described above withrespect to the question, the user device 305 may receive the feedbackvia any type of information, such as audio information, textinformation, image information, etc. In some implementations, when thefeedback is received via audio information, the dialog engine 500 mayconvert the audio information to text information using a speech-to-texttechnique.

Based on the received feedback, a feedback classifier engine 510 maydetermine whether the answer, provided by the answer generation engine505, is a suitable answer for the question received by the answergeneration engine 505. In order to make this determination, the answergeneration engine 505 may receive feedback score information from afeedback score repository 515, which may indicate a score associatedwith the feedback. The feedback score, described further below withrespect to FIG. 6, may indicate how to interpret the feedback. In someimplementations, as similarly described above, the feedback score may beassociated with the exact feedback and/or may be similar to thefeedback, beyond at least a similarity threshold.

The feedback classifier engine 510 may identify that the feedback isassociated with a question-answer pair. For example, the question-answerpair may be associated with a question that was asked and/or an answerthat was provided within a threshold time of the received feedback—e.g.,within fifteen seconds, thirty seconds, one minute, etc. of the receivedfeedback. For instance, assume that user answer generation engine 505provides the answer “Gigli” ten seconds before receiving the feedback“That can't be right.” The feedback classifier engine 510 may determinethat the received feedback is associated with the question-answer pairthat includes the question “What was the highest grossing romanticcomedy of 2003?” and the answer “Gigli.”

Additionally, or alternatively, the feedback classifier engine 510 maydetermine that the received feedback is associated with the lastquestion that was asked and/or the last answer that was provided, ifthere was no other feedback provided. For example, the feedbackclassifier engine 510 may receive the feedback “That can't be right”twenty minutes after providing the answer “Gigli.” Assume, for thisexample, that the feedback classifier engine 510 has not received otherfeedback between providing the answer and receiving the feedback “Thatcan't be right.” The feedback classifier engine 510 may determine thatthe received feedback is associated with the question-answer pair thatincludes the question “What was the highest grossing romantic comedy of2003?” and the answer “Gigli.” In some such implementations, thisdetermination may be made independent of whether a threshold time wasexceeded between the question being received, the answer being provided,and/or the feedback being received.

In some implementations, when identifying the question-answer pair, thefeedback classifier 510 may omit one or more words and/or charactersassociated with the feedback, the question, and/or the answer. Forinstance, continuing with the above example, the feedback classifierengine 510 of some implementations may determine that the feedback “Thatcan't be right” is associated with a question-answer pair that includesa modified version of the question, e.g., “highest grossing romanticcomedy 2003,” and the answer “Gigli.”

A question-answer pair scoring engine 535 may, in some implementations,generate a question-answer pair based on a received question and answer.Additionally, or alternatively, the question-answer pair scoring engine535 may receive information regarding question-answer pairs from aquestion-answer pair score repository 520, and may identify that thereceived question and/or answer is associated with information receivedfrom the question-answer pair score repository 520. The informationreceived from the question-answer pair score repository 520 may includequestion-answer pairs and associated question-answer pair scores. Asfurther described below with respect to FIG. 7, these question-answerpair scores may indicate the strength of answers to associatedquestions.

The question-answer pair scoring engine 535 may generate or modifyquestion-answer pair scores based on the received feedback. For example,the feedback classifier engine 510 may identify that the feedback “Thatcan't be right” is associated with a feedback score that reflects thatthe feedback “That can't be right” is negative feedback, such as a scoreof 0.0 on a scale of 0.0-1.0. Additionally, the feedback classifierengine 510 may identify that the question-answer pair score, for thequestion “What was the highest grossing romantic comedy of 2003?” andthe answer “Gigli,” is 0.1, on a scale of 0.0-1.0. In other words, theanswer “Gigli” may be considered as not a strong answer for the question“What was the highest grossing romantic comedy of 2003?” Based onidentifying the feedback score, the feedback classifier engine 510 maycommunicate with the question-answer pair scoring engine 535 to adjustthe question-answer pair score. For example, the question-answer pairscoring engine 535 may increase or decrease the question-answer pairscore based on the feedback as classified by the feedback classifierengine 510.

Assume, for example, that a question-answer pair, for the question “Whatwas the highest grossing romantic comedy of 2003?” and the answer“Gigli,” is not received from the question-answer pair score repository520. The question-answer pair scoring engine 535 may generate aquestion-answer pair for the question “What was the highest grossingromantic comedy of 2003?” and the answer “Gigli.” In such an example,the question-answer pair scoring engine 535 may generate aquestion-answer pair score for the question-answer pair. In someimplementations, the question-answer pair score may be a default scorethat is in the middle of possible scores. For example, assume that therange of possible question-answer scores is 0.0-1.0. In this example,the question-answer pair scoring engine 535 may assign a question-answerpair score of 0.5 to the question-answer pair. In some implementations,the default question-answer pair score may be a score that is not in themiddle of possible scores. For example, the default score may be 0.0,0.1, 0.4, 0.6, 0.8, 0.9, or any other score within the range of possiblescores.

When adjusting the question-answer pair score, the question-answer pairscoring engine 535 may use any mathematical operation that involves thefeedback score and/or other feedback scores associated with thequestion-answer pair scores and identified by the feedback classifierengine 510—e.g., other feedback scores that are based on feedbackprovided by users of one or more other user devices 305. For example,the question-answer pair scoring engine 535 may average the feedbackscore with other feedback scores associated with the question-answerpair score, may add a value based on the feedback score to thequestion-answer pair score, may multiply the question-answer pair scoreby a value that is based on the feedback score, or may perform any otheroperation that is based on the feedback score and the question-answerpair score.

In some implementations, the question-answer pair scoring engine 535 mayprovide the generated or modified question-answer pair score to thequestion-answer pair score repository 520. The question-answer pairscore repository 520 may update information, stored by thequestion-answer pair score repository 520, based on the generated ormodified question-answer pair score. For example, the question-answerpair scoring repository 520 may replace a stored question-answer pairscore for the question “What was the highest grossing romantic comedy of2003?” and the answer “Gigli” with the modified question-answer pairscore received from the question-answer pair scoring engine 535.

As mentioned above, the feedback score repository 515 may storeinformation regarding various feedback, such as feedback scores. In someimplementations, the feedback score repository 515 may be a part of thefeedback classifier engine 510. In some other implementations, thefeedback repository 515 may be separated from the feedback classifierengine 510. In some implementations, the feedback score repository 515may be implemented as one or more devices, such as the feedback scorerepository server 315, that are separate from the user device 305.Additionally, or alternatively, some or all of the information stored bythe feedback score repository 515 may be stored by the user device 305.An example table of information that may be stored by the feedback scorerepository 515 is described below with respect to FIG. 6.

As also mentioned above, the question-answer pair score repository 520may store information regarding various question-answer pairs, such asquestion-answer pair scores. In some implementations, thequestion-answer pair score repository 520 may be implemented as one ormore devices, such as the question-answer pair score repository server310, that are separate from a user device 305. Additionally, oralternatively, some or all of the information stored by thequestion-answer pair score repository 520 may be stored by a user device305. An example table of information that may be stored by thequestion-answer pair score repository 520 is described below withrespect to FIG. 7.

An activity reporting engine 525 may receive additional activity relatedto the answer or the feedback. The activity reporting engine 525 mayprovide information identifying the additional activity to the answergeneration engine 505 and/or to the feedback classifier engine 510. Forexample, a user may initiate a search, call a telephone number, send ane-mail, or perform any other activity after the answer generation engine505 provides a response. In some implementations, the feedbackclassifier engine 510 may determine that the activity is feedback to theanswer based on the relationship between the answer and the activity. Asanother example, a user may perform a follow-up activity after thefeedback classifier engine 510 receives feedback.

A feedback score generation engine 530 may analyze the feedback and/orthe additional activity, in addition to the question and/or the answerin some implementations, in order to generate or modify a feedback scoreassociated with the feedback. For example, if a user repeats aquestion—e.g., the same question and/or a semantically similarquestion—either after providing feedback or as a part of the feedback,the feedback score generation engine 530 may identify that the providedfeedback is associated with a poor answer. Accordingly, the feedbackscore generation engine 530 may reduce a feedback score associated withthe feedback, and/or generate a feedback score that indicates thefeedback is associated with a poor answer.

Assume, as another example, that a user provides a follow-up question,that is associated with a topic of an answer provided by the answergeneration engine 505. In this example, the feedback classifier engine510 may identify that the provided feedback is associated with a stronganswer. Accordingly, the feedback score generation engine 530 mayincrease a feedback score associated with the feedback, and/or generatea feedback score that indicates the feedback is associated with a stronganswer. Other examples of additional activity by a user, that mayindicate that feedback from the user is associated with a strong answer,may include the user initiating a search that is unrelated to thequestion, the user calling a phone number associated with the answer,the user sending an email to an email address associated with theanswer, etc. The feedback score generation engine 530 may provide thegenerated or modified feedback scores to the feedback score repository515.

As mentioned above, the answer generation engine 505 may provide afollow-up answer when a user expresses dissatisfaction with ananswer—e.g., when a feedback score, based on feedback received by thefeedback classifier engine 510 and/or based on additional activityreceived by the activity reporting engine 525, is below a thresholdfeedback score. Continuing with the above example, as shown in FIG. 2E,the answer generation engine 505 may provide the follow-up answer “Howto Lose a Guy in 10 Days,” based on the feedback, “That can't be right,”received by the feedback classifier engine 510. The answer generationengine 505 may select the follow-up answer from a set of candidateanswers that have been identified in response to the question.

For example, and as discussed above, the answer generation engine 505may select, for the follow-up answer, a question-answer pair with asecond highest score, out of question-answer pairs that are associatedwith the received question—in a scenario where the user providednegative feedback in response to an answer based on the question-answerpair with the highest score. Furthermore, and as also mentioned above,the follow-up answer may additionally, or alternatively, be based on oneor more search results received from a search engine such as the searchengine server 320.

Thus, in some implementations, the answer generation engine 505 mayprovide a follow-up answer based on the feedback received by thefeedback classifier engine 510. In some implementations, the answergeneration engine 505 may provide a follow-up answer based on additionalactivity, received by the activity reporting engine 525 and subsequentto feedback received by the feedback classifier engine 510.Additionally, or alternatively, the feedback score generation engine 530may use additional activity, received by the activity reporting engine525 and subsequent to the feedback received by the feedback classifierengine 510, to generate or modify a feedback score associated with thefeedback received by the feedback classifier engine 510.

Although examples of scores were discussed above with respect to FIG. 5,some implementations may use different scores, and/or ranges of scores,to implement similar concepts as described above. For example, while oneexample score range is 0.0-1.0, other score ranges are possible, such as0-100, 1-10, 2-7, −100 through −1, or any other score range.Additionally, where some implementations use scores at a high end of ascore range, e.g., as an indication of strength of an answer to aquestion, other implementations may use scores at a low end of a scorerange. For example, in one such implementation, a feedback of “that'sright” may be associated with a feedback score of −100, −0.1, 0.0, 0.1,etc., while a feedback of “that's wrong” may be associated with afeedback score of 0.9, 1.0, 9, 10, 90, 100, etc.

Although FIG. 5 shows example functional components of the dialog engine500, in other implementations, the dialog engine 500 may include fewer,different, or additional functional components than depicted in FIG. 5.In still other implementations, one or more functional components of thedialog engine 500 may perform the tasks performed by one or more otherfunctional components of the dialog engine 500.

Furthermore, one or more servers, such as one or more of the serversshown in FIG. 3, may perform the tasks performed by one or morefunctional components of the dialog engine 500. For example, thequestion-answer pair score repository server 310 may perform thefunctions of the question-answer pair score repository 520, and/or thefeedback score repository server 315 may perform the functions of thefeedback score repository 515. In one such implementation, informationthat a user device 305 provides to and/or receives from thequestion-answer pair score repository 520 and/or the feedback scorerepository 515 may be provided to and/or received from thequestion-answer pair score repository server 310 and/or the feedbackscore repository server 315, respectively. In some implementations, thequestion-answer pair score repository server 310 may perform thefunctions of the question-answer pair score repository 520 in lieu ofthe question-answer pair score repository 520 performing such functions,and/or the feedback score repository server 315 may perform thefunctions of the feedback score generation engine 530 in lieu of thequestion-answer pair score repository 520 performing such functions. Insome such implementations, information that a user device 305 wouldprovide to and/or receive from the question-answer pair score repository520 and/or the feedback score repository 515 may be instead provided toand/or received from the question-answer pair score repository server310 and/or the feedback score repository server 315, respectively.

Furthermore, in some implementations, the feedback classifier engine 510may receive additional activity information from one or more useractivity logs, in addition to, or in lieu of, receiving additionalactivity information from the activity reporting engine 525. Forexample, a user activity log repository server may store user activitylogs associated with multiple users, including additional activityinformation, question-answer activity, and/or feedback activity. Theactivity reporting engine 525 may receive user activity information fromsuch a user activity log repository server.

FIG. 6 illustrates an example data structure 600 that may be stored by afeedback score repository, such as feedback score repository server 315and/or one or more devices that implement the feedback score repository515. Data structure 600 may associate feedback, such as feedbackreceived by the feedback classifier engine 510 or predetermined feedbacktypes, may be associated with a respective feedback score. Assume thatthe feedback scores are associated with a range of 0.0-1.0, with 0.0being associated with feedback that indicates that an answer is a pooranswer, and with 1.0 being associated with feedback that indicates thatan answer is a strong answer.

In the example shown in FIG. 6, the feedback “Awesome thanks” and thefeedback “Great answer” may be associated with a feedback score of 1.0,the feedback “Maybe” and the feedback “I guess” may be associated with afeedback score of 0.5, the feedback “That may not be right” may beassociated with a feedback score of 0.2, and the feedback “That's wrong”and the feedback “Wrong answer” may be associated with a feedback scoreof 0.0. As discussed above, other score ranges are possible in practice.As further discussed above, in some implementations, a higher score maybe associated with a feedback that indicates that an answer is a pooreranswer, while a lower score may be associated with a feedback thatindicates that an answer is a stronger answer.

FIG. 7 illustrates an example data structure 700 that may be stored by aquestion-answer score repository, such as the question-answer pair scorerepository server 310 and/or one or more devices that implement thequestion-answer pair score repository 520. Data structure 700 mayassociate question-answer pairs with a question-answer pair score.Assume that, the question-answer pair scores are associated with a rangeof 0.0-1.0, with 0.0 being associated with a poorest answer, and with1.0 being associated with a strongest answer.

Each row, of rows 705-735, may be associated with a particularquestion-answer pair. For example, row 705 may be associated with thequestion-answer pair that includes the question “Who invented thetelephone?” and “Alexander Graham Bell,” and an associatedquestion-answer pair score of 0.9. Row 710 may be associated with thequestion-answer pair that also includes the question “Who invented thetelephone?” The answer associated with the question-answer pair in row710 may be a different answer than that associated with thequestion-answer pair in row 705. Specifically, in the example shown inFIG. 7, the answer associated with the question-answer pair of row 710is “Marty McFly.” The associated question-answer pair score may be 0.1,which may indicate that “Marty McFly” is a poor answer for the question“Who invented the telephone.”

As is apparent from the example shown in FIG. 7, in someimplementations, data structure 700 may store multiple question-answerpairs that are associated with the exact same question—e.g., thequestion-answer pairs shown in rows 705 and 710 are both associated withthe question “Who invented the telephone?” Additionally, oralternatively, data structure 700 may store a single question-answerpair for a single question—e.g., the question-answer pair of row 715includes a question that is not associated with any otherquestion-answer pairs stored by data structure 700. Additionally, oralternatively, data structure 700 may store multiple question-answerpairs that include similar questions—e.g., the question-answer pair ofrow 730 includes the question “What is the best Canadian band?”, whilethe question-answer pair of row 735 includes the question “Who is thebest band from Canada?”

While data structures 600 and 700 are represented in FIGS. 6 and 7,respectively, as tables with rows and columns, in practice, datastructures 600 and 700 may include any type of data structure, such as alinked list, a tree, a hash table, a database, or any other type of datastructure. Data structures 600 and/or 700 may include informationgenerated by a user device 305, or by one or more functional componentsdescribed above with respect to FIG. 5. Additionally, or alternatively,data structures 600 and/or 700 may include information provided from anyother source, such as information provided by one or more users, and/orinformation automatically provided by one or more other devices.

In some implementations, data structures 600 and/or 700 may omitpunctuation. Alternatively, data structures 600 and/or 700 may includepunctuation, such as question marks associated with questions, periods,commas, apostrophes, hyphens, and/or any other type of punctuation.

FIGS. 8 and 9 illustrate flowcharts of example processes for generatingor modifying a score for a question-answer pair based on user feedback.The processes 800 and 900 will be described as being performed by acomputer system comprising one or more computers, for example, the userdevice 305, and/or one or more of the servers 310-320 as shown in FIG.3, and/or the dialog engine 500 as shown in FIG. 5. However, for thesake of simplicity, processes 800 and 900 are described below as beingperformed by the user device 305.

Process 800, shown in FIG. 8, may include receiving a question (block805). In some implementations, receiving a question may includereceiving, by a dialog engine, a first input that specifies a question,where the first input may be spoke input. For example, as describedabove with respect to the answer generation engine 505, the user device305 may receive a question, such as an audible question spoken by auser. Referring to the example scenario shown in FIG. 1A, user device305 may receive the question “Who invented the telephone?”

Process 800 may further include generating an answer that is responsiveto the question (block 810). For example, as described above withrespect to the answer generation engine 505, the user device 305 mayreceive or generate an answer to the question received at block 805. Forinstance, as described above, the user device 305 may use informationstored in the question-answer pair score repository server 310 and/orinformation received from the search engine server 320 when generatingan answer at block 810.

Process 800 may also include outputting the answer (block 815). In someimplementations, outputting the answer may include providing, by thedialog engine, an answer to the question. For example, as describedabove with respect to the answer generation engine 505, the user device305 may output the answer, generated at block 810, via an audio outputdevice, a visual output device, or any other technique of outputtinginformation. Referring to the example scenario shown in FIG. 1B, userdevice 305 may output the answer “Alexander Graham Bell.”

Process 800 may additionally include receiving feedback (block 820). Forexample, as described above with respect to question-answer pair scoringengine 510, user device 305 may receive feedback, such as audiblefeedback spoken by the user. Referring to the example scenario shown inFIG. 1C, user device 305 may receive the feedback “Thanks.”

In some implementations, receiving feedback may include receiving, bythe dialog engine, a second input, where the second input may be spokeninput, and determining, by the dialog engine, that the second input isclassified as feedback to the answer. For example, determining that thesecond input is classified as feedback may include determining that atime difference between a time associated with providing the answer anda time associated with receiving the second input is within apredetermined time. As another example, determining that the secondinput is classified as feedback may include determining that the secondinput is received after providing the answer to the question. As anotherexample, determining that the second input is classified as feedback mayinclude determining that the second input is semantically similar to thefirst input. As another example, determining that the second input isclassified as feedback may include identifying an action associated withthe second input, where the action may be calling a telephone numberassociated with the answer, or sending an email to an email addressassociated with the answer.

Process 800 may further include identifying a feedback score for thereceived feedback (block 825). In some implementations, identifying afeedback score for the received feedback may include determining afeedback score associated with the second input after determining, bythe dialog engine, that the second input is classified as feedback tothe answer. In some implementations, identifying a feedback score mayinclude identifying, by the system, a predetermined feedback scoreassociated with the feedback. In some implementations, identifying apredetermined feedback score associated with the feedback may includenormalizing the feedback; and identifying the predetermined feedbackscore based on the normalized feedback. For example, as described abovewith respect to the feedback classification engine 510, the user device305 may receive or generate a feedback score for the feedback receivedat block 820. Assume, for instance, that the user device 305 identifiesa feedback score of 1.0 for the feedback “Awesome thanks.” The userdevice 305 may determine that the feedback “Awesome thanks” is similarto the feedback “Thanks,” received at block 820, and may thus associatethe feedback score of 1.0 for the feedback “Thanks.”

Process 800 may also include generating or modifying a question-answerpair score based on the feedback score (block 830). For example, asdescribed above with respect to question-answer pair scoring engine 535,the user device 305 may generate or modify a question-answer pair scorebased on the feedback score received at block 825. Continuing with theabove example, the user device 305 may identify a previousquestion-answer pair score of 0.9 for a question-answer pair thatincludes the question “Who invented the telephone?” and the answer“Alexander Graham Bell.” For instance, the question-answer pair scoringengine 535 of user device 305 may receive the previous question-answerpair score of 0.9 from the question-answer pair score repository server310.

The user device 305 may modify the previous question-answer pair scoreof 0.9 based on the predetermined feedback score of 1.0, associated withthe feedback “Thanks.” In some implementations, the system may determinethe predetermined feedback score is higher than a threshold, andclassify the feedback as positive feedback, where the confidence scoremay be adjusted higher based on classifying the feedback as positivefeedback. For example, the user device 305 may increase the previousquestion-answer pair score based on the feedback score. As mentionedabove with respect to the question-answer pair scoring engine 535, userdevice 305 may adjust a question-answer pair score, at block 830, usingone or more of a variety of techniques. In some implementation,generating or modifying a question-answer pair score may includeadjusting a confidence score associated with the answer based on thepredetermined feedback score. One additional such technique is describedbelow with respect to FIG. 9.

Process 800 may additionally include associating the generated ormodified a question-answer pair score with a correspondingquestion-answer pair (block 835). For example, as described above withrespect to the question-answer pair scoring engine 535, the user device305 may store, e.g., in the question-answer pair score repository 520,and/or output, e.g., to the question-answer pair score repository server310, the question-answer pair score generated or modified at block 830.

These question-answer pair scores may be used for any number of reasons.For example, these question-answer pair scores may be used whenproviding answers to additional questions. In some implementations, thesystem may determine the predetermined feedback score is lower than athreshold, and may classify the feedback as negative feedback, where theconfidence score may be adjusted lower based on classifying the feedbackas negative feedback. After adjusting the confidence score associatedwith the answer, the system may identify a second answer to thequestion, wherein the second answer has a higher confidence score thanthe adjusted confidence score associated with the answer, and mayprovide, to the user device 305, the second answer. Additionally, oralternatively, attributes associated with questions, answers,question-answer pairs, and/or question-answer pair scores may be used totrain models, such as search engine and/or document ranking models.

As discussed above, process 900, shown in FIG. 9, may correspond toblock 825 of FIG. 8. In some implementations, when performing process900, a device that performs process 900, such as user device 305 and/orany other device, may utilize multiple feedback score thresholds inorder to determine whether to adjust a question-answer pair score. Somesuch implementations may allow user device 305 to adjust aquestion-answer pair score only when confidence is high that particularfeedback is positive or negative.

Process 900 may include determining whether a feedback score, such asthe feedback score generated at block 825, is greater than a firstthreshold (block 905). For example, user device 305 may determinewhether a feedback score, received at block 825, is greater than a firstthreshold score. Assume, for example, that the feedback score is 1.0,and that the first threshold score is 0.8. In such a scenario, userdevice 305 may determine that the feedback score is above the firstthreshold score.

If the feedback score is greater than the first threshold score (block905—YES), then process 900 may include increasing a question-answer pairscore based on the feedback score (block 910). In some implementation, aquestion-answer pair score may be a confidence score associated with theanswer, and increasing the question-answer pair score may includeclassifying the feedback as positive feedback, where the confidencescore is adjusted higher based on classifying the feedback as positivefeedback. For example, as discussed above with respect to thequestion-answer pair scoring engine 510, the user device 305 mayincrease a question-answer pair score for a question-answer pair thatincludes a question received at block 805 and/or an answer provided atblock 810 based on the feedback score received at block 825. Assume, forinstance, that the question-answer pair score for a question-answer pairis 0.7. Based on determining that a feedback score associated with thequestion-answer pair is greater than the first threshold score (at block905—YES), user device 305 may increase the score to, for example, 0.75,0.8, or some other value.

If, on the other hand, the feedback score is not greater than the firstthreshold score (block 905—NO), then process 900 may include determiningwhether the feedback score is less than a second threshold score (block915). In some implementations, the second threshold score is less thanthe first threshold score. In one such implementation, the first andsecond threshold scores may be separated by some amount. For example,assume that the first threshold score is 0.8. In this example, the lowthreshold score may be 0.2, 0.1, or some other value that is less than0.8.

If the feedback score is less than the second threshold score (block915—YES), then process 900 may include decreasing a question-answer pairscore based on the feedback score (block 920). In some implementations,a question-answer pair score may be a confidence score associated withthe answer, and decreasing a question-answer pair score may includeclassifying the feedback as negative feedback, where the confidencescore is adjusted lower based on classifying the feedback as negativefeedback. For example, as discussed above with respect to thequestion-answer pair scoring engine 510, the user device 305 maydecrease a question-answer pair score for a question-answer pair thatincludes a question received at block 805 and/or an answer provided atblock 810 based on the feedback score received at block 825.

If, on the other hand, the feedback score is not less than the secondthreshold score (block 915—NO) and is not greater than the firstthreshold score (block 905—NO), then process 900 may include foregoingmodifying a question-answer pair score based on the feedback score.Alternatively, in such a scenario, the user device 305 may modify aquestion-answer pair score, but the modification may be less extremethan a modification that would be made if the feedback score weregreater than the first threshold score or less than the second thresholdscore.

In other words, the user device 305 may assign a weight to the feedbackscore when the feedback score is between the first threshold score andthe second threshold score. This weight may be lower than a weightassigned to the feedback score when the feedback score is greater thanthe first threshold score or less than the second threshold score.

While processes 800 and 900 are described above in the example contextof generating or modifying a question-answer pair score based onfeedback from one user, it should be understood that a question-answerpair score may be generated or modified based on feedback received frommultiple users, e.g., multiple users of multiple user devices 305. Insome implementations, the system may receive, from a different userdevice, a second voice input to the provided answer. The system maydetermine that the second voice input represents feedback to the answer.The system may identify a second predetermined feedback score associatedwith the feedback from the different computing device. The system maythen adjust the confidence score associated with the answer based on thefeedback from the user device 305 and the feedback from the differentuser device. In some implementations, a question-answer pair score maynot be generated or modified until at least a threshold amount offeedback is received. For example, assume that the threshold amount offeedback is feedback from ten users, and that feedback is received fromnine users. Once the tenth feedback is received, a question-answer pairscore may be generated or modified. In some implementations, thequestion-answer pair score may be generated or modified based on all tenof the received feedbacks. In some implementations, the question-answerpair score may be generated or modified based on fewer than ten of thereceived feedbacks.

In some implementations, a question-answer pair score may not begenerated or modified until at least a threshold amount of positivefeedback is received, and/or until at least a threshold of negativefeedback is received. For example, assume that the threshold amount ofpositive feedback is positive feedback from five users. Further assumethat positive feedback is received from four users. Once the fifthpositive feedback is received, a question-answer pair score may begenerated or modified. In some implementations, the positive feedbackthreshold may be the same as the negative feedback threshold. Forinstance, assuming the positive feedback threshold is positive feedbackfrom five users, the negative feedback threshold may be negativefeedback from five users. In an alternative implementation, the positivefeedback threshold may be different from the negative feedbackthreshold. For instance, assuming the positive feedback threshold ispositive feedback from five users, the negative feedback threshold maybe negative feedback from ten users.

Additionally, or alternatively, the positive feedback threshold and/orthe negative feedback threshold may be based on an amount by which thefeedback affects a question-answer pair score. For example, assume thatthe positive feedback threshold is 0.1. In this example, aquestion-answer pair score may be modified based on a set of feedback ifthe result of modifying the question-answer pair score is an increase of0.1 or greater, but not if the result of modifying the question-answerpair score is an increase of 0.1 or greater. Assume, as another example,that the negative feedback threshold is 0.1. In this example, aquestion-answer pair score may be modified based on a set of feedback ifthe result of modifying the question-answer pair score is a decrease of0.1 or greater, but not if the result of modifying the question-answerpair score is a decrease of 0.1 or greater. Some implementations mayinclude both a positive feedback threshold and a negative feedbackthreshold. In such implementations, a question-answer pair score may bemodified if the result is an increase of the question-answer pair scoreby least the positive feedback threshold, or a decrease of thequestion-answer pair score by at least the negative feedback threshold.

In some implementations, the positive feedback threshold may be the sameas the negative feedback threshold. For instance, assuming the positivefeedback threshold is 0.1, the negative feedback threshold may be 0.1.In an alternative implementation, the positive feedback threshold may bedifferent from the negative feedback threshold. For instance, assumingthe positive feedback threshold is 0.1, the negative feedback thresholdmay be 0.2.

In some implementations, positive and negative feedback may affect aquestion-answer pair score by the same magnitude, but may have oppositevalues. For example, in such implementations, a positive feedback maycause a question-answer pair score to be increased by 0.01, while anegative feedback may cause the question-answer pair score to bedecreased by 0.01. In other words, in such an example, a positivefeedback may be assigned a value of +0.01, while a negative feedback maybe assigned a value of −0.01.

In some implementations, positive and negative feedback may affect aquestion-answer pair score by a different magnitude. For example, insome such implementations, a positive feedback may cause aquestion-answer pair score to be increased by 0.01, while a negativefeedback may cause the question-answer pair score to be decreased by0.02. In other words, in such an example, a positive feedback may beassigned a value of +0.01, while a negative feedback may be assigned avalue of −0.02.

Although examples of scores were discussed above with respect to FIGS. 8and 9, some implementations may use different scores, and/or ranges ofscores, to implement similar concepts as described above. For example,while one example score range is 0.0-1.0, other score ranges arepossible, such as 0-100, 1-10, 2-7, −100 through −1, or any other scorerange. Additionally, where some implementations use scores at a high endof a score range, e.g., as an indication of strength of an answer to aquestion, other implementations may use scores at a low end of a scorerange. For example, in one such implementation, a feedback of “that'sright” may be associated with a feedback score of −100, −0.1, 0.0, 0.1,etc., while a feedback of “that's wrong” may be associated with afeedback score of 0.9, 1.0, 9, 10, 90, 100, etc.

FIG. 10 illustrates a flowchart for generating or modifying a score foruser feedback. In some implementations, process 1000 may be performed bya computer system comprising one or more computers, for example, theuser device 305, and/or one or more of the servers 310-320 as shown inFIG. 3, and/or the dialog engine 500 as shown in FIG. 5. In someimplementations, process 1000 may be performed by one or more othercomponents instead of, or possibly in conjunction with, the user device305, and/or one or more of the servers 310-320 as shown in FIG. 3,and/or the dialog engine 500 as shown in FIG. 5. However, for the sakeof simplicity, process 1000 is described below as being performed byuser device 305.

Process 1000 may include outputting an answer (block 1005). For example,as discussed above with respect to answer generation engine 505, userdevice 305 may output an answer to a question. Process 1000 may alsoinclude receiving feedback (block 1010). For example, as discussed abovewith respect to the question-answer pair scoring engine 510, the userdevice 305 may receive feedback in response to the answer provided atblock 1005. In some implementations, receiving feedback may includereceiving a second input, and determining that the second input isclassified as feedback to the answer. Process 1000 may further includedetecting additional activity (block 1015). In some implementations,detecting additional activity may include identifying an actionassociated with the second input. For example, as discussed above withrespect to the activity reporting engine 525, the user device 305 maydetect additional activity associated with the feedback received atblock 1010 and/or the answer output at block 1005. In someimplementations, the user device 305 may detect that the additionalactivity was received after the feedback was received at block 1010.

Process 1000 may additionally include generating or modifying a feedbackscore, associated with the feedback, based on the additional activity(block 1020). In some implementations, generating or modifying afeedback score may include determining that the second input isclassified as feedback to the answer, then determining a feedback scoreassociated with the second input. For example, as discussed above withrespect to the feedback score generation engine 530, the user device 305may generate or modify a feedback score based on the additional activitydetected at block 1015. Process 1000 may further include storing thegenerated or modified feedback score (block 1025). For example, asdescribed above with respect to the feedback score generation engine 530and the feedback score repository 515, user device may store thefeedback score generated or modified at block 1020.

FIGS. 11A-12E illustrate examples of generating or modifying a score foruser feedback. As shown in FIG. 11A, a user 105 may ask a question to auser device 110. For example, the user 105 may ask the question “Whatsport did Michael Jordan play?” As shown in FIG. 11B, the user device110 may output an answer, such as “Basketball.” As shown in FIG. 11C,the user 105 may provide feedback, such as “Neat.” As shown in FIG. 11D,the user device 110 may detect additional activity from the user 105,such as the user 105 asking the question “What are the rules ofbasketball?”

As shown in FIG. 11E, the user device 110 may store an indication thatthe feedback—specifically, the user speaking the word “Neat,” in thisexample—may identify that an answer is relevant to an asked question. Inother words, this indication may indicate that this feedback is providedby a user when an answer is a strong answer. The user device 110 maystore this indication based on the additional activity received from theuser—specifically, the asking of the question “What are the rules ofbasketball?”—after the user device 110 has provided the answer“Basketball.” As described above with respect to process 1000, the userdevice 110 may use this indication to modify a feedback score associatedwith the feedback “Neat.” For example, the user device 110 may raise afeedback score associated with the feedback “Neat.”

The additional activity in the above example—i.e., the asking of thequestion, “What are the rules of basketball?”—may indicate that theanswer provided to the question was a strong answer. This additionalactivity may indicate a strong answer because the additional activity isrelated to a topic that the answer is associated with—e.g.,basketball—but does not re-state the question. Since the answer may be astrong answer, the user feedback provided after the answer wasprovided—i.e., “Neat”—may be identified as feedback that is associatedwith a strong answer.

In another example, as shown in FIG. 12A, a user 105 may ask a questionto a user device 110. For example, the user 105 may ask the question“Who wrote the Declaration of Independence?” As shown in FIG. 12B, theuser device 110 may output an answer, such as “John Hancock.” As shownin FIG. 12C, the user 105 may provide feedback, such as “I don't thinkso.” As shown in FIG. 12D, the user device 110 may detect additionalactivity from the user 105, such as the user 105 asking the question“Who was the author of the Declaration of Independence?”

As shown in FIG. 12E, the user device 110 may store an indication thatthe feedback—specifically, the phrase “I don't think so,” in thisexample—may identify that an answer is not relevant to an askedquestion. In other words, this indication may indicate that thisfeedback is provided by a user when an answer is not a strong answer.The user device 110 may store this indication based on the additionalactivity received from the user—specifically, the asking of the question“Who was the author of the Declaration of Independence?”—after the userdevice 110 has provided the answer “John Hancock.” As described abovewith respect to process 1000, the user device 110 may use thisindication to modify a feedback score associated with the feedback “Idon't think so.” For example, the user device 110 may lower a feedbackscore associated with the feedback “I don't think so.”

FIG. 13 illustrates a flowchart of an example process 1300 for providinga follow-up answer based on feedback. In some implementations, process1300 may be performed by a computer system comprising one or morecomputers, for example, the user device 305, and/or one or more of theservers 310-320 as shown in FIG. 3, and/or the dialog engine 500 asshown in FIG. 5. In some implementations, process 1300 may be performedby one or more other components instead of, or possibly in conjunctionwith, the user device 305, and/or one or more of the servers 310-320 asshown in FIG. 3, and/or the dialog engine 500 as shown in FIG. 5.However, for the sake of simplicity, process 1300 is described below asbeing performed by user device 305.

Process 1300 may include receiving a question (block 1305). In someimplementations, receiving a question may include receiving a voiceinput that specifies the question. For example, as described above withrespect to answer generation engine 505, user device 305 may receive aquestion, such as an audible question spoken by a user. Referring to theexample scenario shown in FIG. 2A, user device 305 may receive thequestion “What was the highest grossing romantic comedy of 2003?”

Process 1300 may also include generating an answer that is responsive tothe question (block 1310). For example, as described above with respectto the answer generation engine 505, the user device 305 may receive orgenerate an answer to the question received at block 1305. For example,as described above, the user device 305 may use information stored inthe question-answer pair score repository server 310 and/or informationreceived from the search engine server 320 when generating an answer atblock 1310. As discussed above, the answer may be based on a scoreassociated with a result received from the search engine server 320, ascore associated with a question-answer pair received fromquestion-answer pair score repository 520, or both. For example, theanswer “Gigli” may be associated with a highest score out of scoresassociated with candidate answers.

Process 1300 may further include outputting, or providing, the answer(block 1315). For example, as described above with respect to the answergeneration engine 505, the user device 305 may output the answer,generated at block 1310, via an audio output device, a visual outputdevice, or any other technique of outputting information. Referring tothe example scenario shown in FIG. 2B, user device 305 may output theanswer “Gigli.”

Process 1300 may additionally include receiving feedback (block 1320).In some implementations, receiving feedback may include receiving avoice input, and determining that the received voice input representsfeedback to the answer of the question. For example, as described abovewith respect to the question-answer pair scoring engine 510, the userdevice 305 may receive feedback, such as audible feedback spoken by theuser. Referring to the example scenario shown in FIG. 2C, user device305 may receive the feedback “That can't be right.”

Process 1300 may also include identifying a feedback score for thereceived feedback (block 1325). In some implementations, identifying afeedback score may include identifying a predetermined feedback scoreassociated with the feedback. In some implementations, identifying afeedback score may include normalizing the feedback, identifying thepredetermined feedback score based on the normalized feedback. Forexample, as described above with respect to question-answer pair scoringengine 510, user device 305 may receive or generate a feedback score forthe feedback received at block 1320. Assume, for instance, that userdevice 305 identifies a feedback score of 0.0 for the feedback “Thatcan't be right.”

Process 1300 may further include determining whether the feedback scoreis less than a threshold feedback score (block 1330). For example,assume that the threshold feedback score is 0.2. Continuing with theabove example, user device 305 may determine that the feedback score of0.0, associated with the feedback “That can't be right,” is less thanthe threshold feedback score. In some implementations, the system maydetermine the predetermined feedback score is lower than a threshold,and classify the feedback as negative feedback. In some implementations,the confidence score associated with the answer is adjusted lower basedon classifying the feedback as negative feedback.

If the feedback score is less than the threshold feedback score (block1330—YES), then process 1300 may include generating a follow-up answerthat is responsive to the question (block 1335). In someimplementations, after adjusting the confidence score associated withthe answer, the system may identify a second answer to the question,wherein the second answer has a higher confidence score than theadjusted confidence score associated with the answer. For example, asdescribed above with respect to the answer generation engine 505, theuser device 305 may receive or generate a follow-up answer that isresponsive to the question. For instance, as described above, the userdevice 305 may use information stored in the question-answer pair scorerepository server 310 and/or information received from the search engineserver 320 when generating a follow-up answer at block 1335. Asdiscussed above, the answer may be based on a score associated with aresult received from the search engine server 320, a score associatedwith a question-answer pair received from the question-answer pair scorerepository 520, or both. For example, the answer generated at block 1335may be associated with a score that is not the highest score out ofscores associated with candidate answers—e.g., an answer that isassociated with a second-highest score out of the scores associated withcandidate answers.

For example, assume that the answer “Gigli,” outputted at block 1315, isa highest scoring candidate answer. The user device 305 may identifythat an answer “How to Lose a Guy in 10 Days” is a second-highestscoring candidate answer. The user device 305 may select thesecond-highest scoring candidate answer, and generate the follow-upanswer based on the second-highest scoring candidate answer. Thus, thefollow-up answer may include “How to Lose a Guy in 10 Days.” In someimplementations, the follow-up answer may further include an indicationthat the follow-up answer is a follow-up answer. In theseimplementations, the follow-up answer may be, for example, “‘How to Losea Guy in 10 Days’ may be a better answer,” “Sorry about that, how about‘How to Lose a Guy in 10 Days,’” “Whoops, maybe ‘How to Lose a Guy in 10Days’ is a better answer to your question,” etc.

Process 1300 may further include outputting the follow-up answer (block1340). In some implementations, outputting the follow-up answer mayinclude providing, to a user device, the second answer. For example, asshown in FIG. 2E, the user device 305 may audibly output the phrase“‘How to Lose a Guy in 10 Days’ may be a better answer.” The user device305 may audibly output the follow-up answer using text-to-speech or someother technique. Additionally, or alternatively, the user device 305 mayoutput the follow-up answer visually by, for example, outputting thefollow-up answer via a display device, such as a display screenassociated with the user device 305.

If, on the other hand, the feedback score is not less than the thresholdfeedback score (block 1330—NO), then process 1300 may include foregoinggenerating a follow-up answer (block 1345). Such a scenario may occur,for example, when the user device 305 does not receive negative feedbackregarding the answer outputted at block 1315, when the user device 305does not receive any feedback regarding the answer outputted at block1315, when the user device 305 receives positive feedback regarding theanswer outputted at block 1315, etc.

In some implementations, user device 305 may wait for a particularduration of time to elapse, without receiving or detecting anyadditional activity from the user, before identifying the feedback score(at block 1325), determining whether the feedback score is less than thethreshold feedback score (at block 1330), generating the follow-upanswer (at block 1335), and/or outputting the follow-up answer (at block1340). For example, user device 305 may wait 5 seconds, 10 seconds, oneminute, or any duration of time, after receiving the feedback at 1320.

Assume, for instance, that the particular duration of time is 2 seconds.Further assume that the user device 305 receives (at block 1320)feedback, and then does not receive or detect any additional activityfor 2 seconds after receiving the feedback. After the 2 seconds haveelapsed, the user device 305 may output a follow-up answer (at block1340).

In another scenario, assume still that the particular duration of timeis 2 seconds. Further assume that the user device 305 receives (at block1320) feedback, and then receives or detects additional activity 1second after receiving the feedback. The user device 305 may process theadditional activity in, for example, a manner described above withrespect to FIG. 10. For example, the additional activity may be callinga telephone number associated with the answer, or sending an email to anemail address associated with the answer. The user device 305 may, insome implementations, use the additional activity to generate or modifya feedback score associated with the feedback received at block 1320.

By waiting for the particular duration of time to elapse, the userdevice 305 of some implementations may provide the user with anopportunity to perform additional activity. Thus, in suchimplementations, the user may be more in control of the interactionbetween the user and the user device 305.

In some implementations, the duration of time may be configurable by auser, such as a user of user device 305, a user associated with one ormore of servers 310-320, and/or any other user. In some implementations,the duration of time may be automatically determined or adjusted by userdevice 305, one or more of servers 310-320, and/or any other device. Insome implementations, one user device 305 may be associated with oneduration of time, while another user device 305 may be associated with adifferent duration of time.

In some implementations, user device 305 may not wait for any time toelapse before identifying the feedback score (at block 1325),determining whether the feedback score is less than the thresholdfeedback score (at block 1330), generating the follow-up answer (atblock 1335), and/or outputting the follow-up answer (at block 1340).That is, upon receiving feedback (at block 1320), user device 305 ofsome implementations may identify the feedback score (at block 1325),determine whether the feedback score is less than the threshold feedbackscore (at block 1330), generate the follow-up answer (at block 1335),and/or output the follow-up answer (at block 1340).

While some of the above processes have been described separately, two ormore of the above processes may be performed sequentially, iteratively,and/or in parallel, in some implementations. For instance, FIGS. 14A-14Iillustrate an example of providing a follow-up answer and generating ormodifying a question-answer pair score associated with a question andthe follow-up answer.

As shown in FIG. 14A, a user 105 may ask a question to a user device110. For example, the user 105 may ask the question “In which country isFerrari headquarters located?” As shown in FIG. 14B, the user device 110may output an answer, such as “Belgium.” As shown in FIG. 14C, the user105 may provide feedback, such as “I think that's wrong.” The userdevice 110 may identify a feedback score associated with the feedback “Ithink that's wrong.” Based on the feedback score, and as shown in FIG.14D, the user device 110 may determine that “Belgium” is not a stronganswer to the question “In which country is Ferrari headquarterslocated?” Based on determining that “Belgium” is not a strong answer tothe question, the user device 110 may cause a question-answer pairscore, associated with the question “In which country is Ferrariheadquarters located?” and the answer “Belgium” to be adjusted toreflect that “Belgium” is not a strong answer to the question.

As shown in FIG. 14E, the user device 110 may detect additional activityfrom the user 105, such as the user 105 asking the question “In whichcountry is Ferrari headquarters located?” As mentioned above, the userdevice 110 may wait for a particular duration of time to elapse beforeautomatically providing a follow-up answer, when a user's feedbackindicates the user's dissatisfaction with an answer. In the exampleshown in FIG. 14E, the user device 110 may detect the additionalactivity—i.e., the user repeating the question “In which country isFerrari headquarters located?”—before the particular duration of timehas elapsed.

As shown in FIG. 14F, the user device 110 may store an indication thatthe feedback—specifically, the phrase “I think that's wrong,” in thisexample—may identify that an answer is not relevant to an askedquestion. In other words, this indication may indicate that thisfeedback is provided by a user when an answer is not a strong answer.The user device 110 may store this indication based on the additionalactivity received from the user—specifically, the repetition of thequestion “In which country is Ferrari headquarters located?”—after theuser device 110 has provided the answer “Belgium.” As described abovewith respect to process 1000, the user device 110 may use thisindication to modify a feedback score associated with the feedback “Ithink that's wrong.” For example, the user device 110 may lower afeedback score associated with the feedback “I think that's wrong.”

The user device 110 may determine that the additional activity isrelated to the question asked in FIG. 14A based on, for example, ameasure of similarity—e.g., semantic similarity—of the additionalactivity to the question asked in FIG. 14A. Based on determining thatthe additional activity is related to the question asked in FIG. 14A,and as shown in FIG. 14G, the user device 110 may output the follow-upanswer “‘Italy’ may be a better answer,” in response to the additionalactivity—namely, the repetition of the question “In which country isFerrari headquarters located?” That is, since the user device 110 hasdetermined that the additional activity is related to the question askedin FIG. 14A, the user device 110 may include an indication—e.g., thephrase “may be a better answer”—that the answer outputted at FIG. 14G isa follow-up answer.

As shown in FIG. 14H, the user 105 may provide feedback regarding thefollow-up answer. Specifically, for instance, the user 105 may speak theword “Thanks.” The user device 110 may identify a feedback scoreassociated with the feedback “Thanks.” Based on the feedback score, andas shown in FIG. 14I, the user device 110 may determine that “Italy” isa strong answer to the question “In which country is Ferrariheadquarters located?” Based on determining that “Italy” is a stronganswer to the question, the user device 110 may cause a question-answerpair score, associated with the question “In which country is Ferrariheadquarters located?” and the answer “Italy” to be adjusted to reflectthat “Italy” is a strong answer to the question.

Some implementations, described herein, may allow one or more devices togenerate or modify question-answer pair scores based on user feedback,such as feedback that a user provides after the user device outputs ananswer that responds to the user's question. Additionally, someimplementations may allow one or more devices to automatically providefollow-up answers when a user's feedback indicates that the user isdissatisfied with an answer. Furthermore, some implementations,described herein, may allow one or more devices to generate or modifyfeedback scores that indicate whether feedback, provided by users, isassociated with users' satisfaction, dissatisfaction, or ambivalencewith respect to answers provided in response to questions asked by theusers, based on additional user activity after users provide feedback.

The foregoing description provides illustration and description, but isnot intended to be exhaustive or to limit the implementations to theprecise form disclosed. Modifications and variations are possible inlight of the above description or may be acquired from practice of theimplementations.

For example, while feedback was described in the context of words thatmay be spoken by a user, other type of feedback may be used to scorequestion-answer pairs. For example, a user's facial expressions may beused in addition to, or in lieu of, words spoken by the user in order todetermine user feedback. A video input device, such as a camera,associated with user device 305 may capture one or more images of theface of the user, and may identify feedback based on the captured one ormore images of the face of the user. For example, user device 305 maycompare positions and/or angles of the user's facial features to storedinformation, of positions and/or angles of facial features, that isassociated with user feedback. One or more devices, e.g., feedback scorerepository server 315, may store information associating positionsand/or angles of facial features with feedback and/or feedback scores.

Additionally, or alternatively, audible characteristics of the user'svoice may be identified as feedback. For instance, volume of a user'svoice, inflection of a user's voice, or other characteristics of thevoice of the user may be used in order to identify feedback. Forexample, information, e.g., information stored by feedback scorerepository server 315, may associate vocal characteristics with feedbackand/or feedback scores.

Furthermore, while series of blocks have been described with regard toFIGS. 8-10, the order of the blocks may be modified in otherimplementations. Further, non-dependent blocks may be performed inparallel.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyinventions or of what may be claimed, but rather as descriptions offeatures specific to particular implementations of particularinventions. Certain features that are described in this specification inthe context of separate implementations can also be implemented incombination in a single implementation. Conversely, various featuresthat are described in the context of a single implementation can also beimplemented in multiple implementations separately or in any suitablesubcombination. Moreover, although features may be described above asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multitasking and parallel processingmay be advantageous. Moreover, the separation of various systemcomponents in the implementations described above should not beunderstood as requiring such separation in all implementations, and itshould be understood that the described program components and systemscan generally be integrated together in a single software product orpackaged into multiple software products.

Thus, particular implementations of the subject matter have beendescribed. Other implementations are within the scope of the followingclaims. In some cases, the actions recited in the claims can beperformed in a different order and still achieve desirable results. Inaddition, the processes depicted in the accompanying figures do notnecessarily require the particular order shown, or sequential order, toachieve desirable results. In certain implementations, multitasking andparallel processing may be advantageous.

What is claimed is:
 1. A computer-implemented method comprising: providing, by a dialog engine of a computing device, an answer to a question; after providing the answer to the question, receiving, by the dialog engine, a voice input; determining, by the dialog engine, that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer to the question; identifying, by the dialog engine, a predetermined feedback score that reflects an extent to which, in response to other questions, other users express satisfaction or dissatisfaction when speaking a particular term that is included in the received voice input; adjusting, based at least on the predetermined feedback score that is associated with a transcription of the received voice input, a confidence score that, based on prior selections of the provided answer to the question by other users, indicates an estimation of relevance of the provided answer to the question; and in response to a subsequent receipt of the question, selecting, by the answer generation engine, the answer or a different answer based at least on the adjusted confidence score.
 2. The method of claim 1, wherein the predetermined feedback score is determined after determining that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer to the question.
 3. The method of claim 1, wherein the predetermined feedback score is determined before determining that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer to the question.
 4. The method of claim 1, comprising: before providing the answer to the question: receiving an initial voice input that specifies the question; determining a confidence score associated with a question-answer pair that comprises (i) the question, and (ii) the provided answer to the question; and determining to provide the provided answer to the question based on the confidence score associated with the question-answer pair.
 5. The method of claim 1, wherein determining that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer comprises: determining an amount of time that elapses between providing the answer to the question and receiving the voice input; and determining that the amount of time that elapses between providing the answer to the question and receiving the voice input is less than a predetermined amount of time.
 6. The method of claim 1, wherein determining that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer comprises: determining (i) a semantic measure associated with the question, and (ii) a semantic measure associated with the provided answer to the question; and determining that (i) the semantic measure associated with the question, and (ii) the semantic measure associated with the provided answer to the question, satisfy a predetermined semantic measure similarity threshold.
 7. The method of claim 1, wherein determining that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer comprises: identifying an action performed by a user of the computing device after the voice input was received.
 8. The method of claim 7, wherein the action performed by the user of the computing device includes dialing a telephone number that is associated with the answer, or composing an email to an email address that is associated with the answer.
 9. The method of claim 1, wherein identifying a predetermined feedback score that is associated with the transcription of the received voice input further comprises: normalizing the transcription of the received voice input; and identifying the predetermined feedback score that is associated with the normalized transcription.
 10. The method of claim 1, further: after adjusting the confidence score that is associated with the provided answer to the question: identifying a different question-answer pair that (I) comprises (i) the question, and (ii) a different answer to the question, and (II) is associated with a different confidence score that is higher than the confidence score that is associated with the question-answer pair that comprises (i) the question, and (ii) the provided answer to the question; and providing, to the computing device, the different answer to the question.
 11. The method of claim 1, wherein the subsequent receipt of the question is based on a question that originated with a user that is different than the user that originated the received voice input.
 12. A system comprising: a non-transitory computer readable medium having instructions stored thereon; and data processing apparatus programmed to execute the instructions to perform operations comprising: providing, by a dialog engine, an answer to a question; after providing the answer to the question, receiving, by the dialog engine, a voice input; determining, by the dialog engine, that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer to the question; identifying, by the dialog engine, a predetermined feedback score that reflects an extent to which, in response to other questions, other users express satisfaction or dissatisfaction when speaking a particular term that is included in the received voice input; adjusting, based at least on the predetermined feedback score that is associated with a transcription of the received voice input, a confidence score that, based on prior selections of the provided answer to the question by other users, indicates an estimation of relevance of the provided answer to the question; and in response to a subsequent receipt of the question, selecting, by the answer generation engine, the answer or a different answer based at least on the adjusted confidence score.
 13. The system of claim 12, wherein the predetermined feedback score is determined after determining that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer to the question.
 14. The system of claim 12, wherein the predetermined feedback score is determined before determining that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer to the question.
 15. The system of claim 12, wherein the operations comprise: before providing the answer to the question: receiving an initial voice input that specifies the question; determining a confidence score associated with a question-answer pair that comprises (i) the question, and (ii) the provided answer to the question; and determining to provide the provided answer to the question based on the confidence score associated with the question-answer pair.
 16. The system of claim 12, wherein determining that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer comprises: determining an amount of time that elapses between providing the answer to the question and receiving the voice input; and determining that the amount of time that elapses between providing the answer to the question and receiving the voice input is less than a predetermined amount of time.
 17. The system of claim 12, wherein determining that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer comprises: determining (i) a semantic measure associated with the question, and (ii) a semantic measure associated with the provided answer to the question; and determining that (i) the semantic measure associated with the question, and (ii) the semantic measure associated with the provided answer to the question, satisfy a predetermined semantic measure similarity threshold.
 18. The system of claim 12, wherein determining that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer comprises: identifying, after the voice input was received, an action performed by a user of a computing device that includes the dialog engine.
 19. The system of claim 12, wherein identifying a predetermined feedback score that is associated with the transcription of the received voice input further comprises: normalizing the transcription of the received voice input; and identifying the predetermined feedback score that is associated with the normalized transcription.
 20. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a processor, cause the processor to perform operations comprising: providing, by a dialog engine, an answer to a question; after providing the answer to the question, receiving, by the dialog engine, a voice input; determining, by the dialog engine, that the received voice input is classified as feedback that indicates satisfaction or dissatisfaction with the provided answer to the question; identifying, by the dialog engine, a predetermined feedback score that reflects an extent to which, in response to other questions, other users express satisfaction or dissatisfaction when speaking a particular term that is included in the received voice input; adjusting, based at least on the predetermined feedback score that is associated with a transcription of the received voice input, a confidence score that, based on prior selections of the provided answer to the question by other users, indicates an estimation of relevance of the provided answer to the question; and in response to a subsequent receipt of the question, selecting, by the answer generation engine, the answer or a different answer based at least on the adjusted confidence score. 